Snowmobiles are normally propelled by a resilient belt track driven by drive wheels. Conventional belt tracks typically have transverse lugs for traction. To improve traction, it is well known to mount studs in the belting of the track between the transverse lugs. Snowmobile studs are typically made of hardened carbon steel or other steel alloys for strength and durability purposes. Most studs for ice tracks have a conical, ice-penetrating shank made of hardened steel with an ice-penetrating point which is often carbide.
One common type of stud is a “push-through stud”. With a push-through stud, a shank of the stud typically projects perpendicularly from a head of the stud, and the shank is pushed through a bore in the belt track from the interior of the track such that the head contacts the interior side of the track. A backer plate or washer can be tightened onto threads on the shank from the exterior of the belt with a nut. In this manner, any axial movement, i.e., any substantial movement of the head toward or away from the track, is prevented.
Such a connection is sufficient for studs having a straight shank which is perpendicular to the head since rotation of straight studs does not affect traction performance.
However, the Applicant has found that studs including bent shanks can improve snowmobile performance. Studs may include a bent distal tip in order to improve penetration and traction performance. Such bent studs are particularly useful in racing conditions. The bent studs may be connected to a track in the same manner as straight studs, with a nut or similar fastener connected to the stud along the portion of its shank which is perpendicular to the head. When connected, the bent distal tip is “aimed” forward such that when the track moves toward the ground the tip leads the rest of the stud. For studs with shanks that include portions which are not perpendicular to the head, rotation of the stud can severely affect performance. It has been found that in order to prevent rotation of bent studs, the fastener must be frequently tightened as far as possible and the track must be repeatedly checked to ensure that each stud is properly aligned.
While such maintenance can be effective, it is time consuming and is not likely to be accommodated by trail riders or other recreational snowmobilers. Therefore, bent studs would be avoided by such snowmobilers. However, bent studs could provide great benefits to such snowmobilers since the improved traction performance of bent studs allows for use of fewer studs on a track and, therefore, less rotating weight on the track and better performance—including increased fuel efficiency and better acceleration.
Furthermore, bent studs experience great amounts of torque, shear and other forces during use. When racing, due to short term use, worn out or damaged bent studs could be replaced often. However, such frequent replacement is expensive and time consuming.
Therefore, it would be a great advance in the field of snowmobiling to allow for use of bent studs which are locked in position both axially and rotationally. In addition, it would be a great advance in the field to reduce torque and other forces on bent studs to allow for longer use. Furthermore, it would be a great advance to provide a method of commercially producing standardized bent studs for use in snowmobiling.